As a system for a projector to perform trapezoidal distortion correction (also referred to as trapezoid correction, keystone correction, and the like), for example, the following systems are proposed: a system for a user to designate a desired vertex among four vertexes of an image and adjust a vertex position as described in Japanese Patent Publication No. 2005-286572; a system for detecting a frame of a screen in a pickup image and adjusting the pickup image according to the frame as described in Japanese Patent Publication No. 2006-60447; and a system for pressing up, down, left, and right buttons of a projector main body to adjust distortion in a trapezoidal shape.
For example, a projector is proposed that adopts a system for a user to press, when succeeding in detection of a frame of a screen, up, down, left, and right buttons of a projector main body after automatic trapezoidal distortion correction corresponding to the frame to thereby perform manual trapezoidal distortion correction in the system for designating a desired vertex among four vertexes of an image and adjusting a vertex position and press, when failing in the detection, the up, down, left, and right buttons of the projector main body to thereby perform the manual trapezoidal distortion correction in the system for adjusting distortion in a trapezoidal shape.
However, the system is a system for performing trapezoidal distortion correction in the different systems, although the same operation buttons are pressed. Therefore, in some case, the user is confused.